I noticed in one of your photos that you are using one of those 3M yellow long boards. I bought the same one about 4 years ago, and after many sessions of skimming and blocking I realized this thing was not flat. Sure enough with a simple test on a perfect flat edge this thing was only touching on the two outside edges, the center was bowed in. Bottom line I dont care who you are, if your blocks are not flat you will never get the panels straight. Do yourself a favor check all your blocks and see just how flat they really are. I ended up cutting different lenghts of 3/8 plexi glass and using that 3M block as a very expensive handle for a truly flat longboard.